Patent Application
20180072812
The presently disclosed subject matter generally relates to composition and method for treating diseases associated with aberrant integrin αvβ3 expression in a subject. More particularly, the method relates to administering to the subject an effective amount of a composition comprising a pyruvate kinase isoform M2 (PKM2) antagonist that inhibits the binding of PKM2 to integrin αvβ3.
A substantial and persuasive body of data now exists that supports the view that integrin αvβ3 plays a critical part in activated macrophage dependent inflammation, osteoclast development, migration, and bone resorption, and inflammatory angiogenesis. All of these processes play an important part in the pathogenesis of rheumatoid arthritis (RA) and related arthropathies. Therefore, agents are needed that specifically inhibit aberrant integrin αvβ3 activity.
As disclosed herein, pyruvate kinase isoform M2 (PKM2) promotes myofibroblast differentiation by acting on integrin αvβ3. Therefore, methods are disclosed for disrupting or preventing the interaction of PKM2 and integrin αvβ3. The methods involve administering to a subject an effective amount of a composition comprising a PKM2 antagonist that inhibits the binding/interaction of PKM2 to integrin αvβ3. The PKM2 antagonist can be any molecule that effectively inhibits this interaction by binding PKM2 at or near the integrin interaction sites. For example, the PKM2 antagonist can be an antibody (e g humanized antibody or fragments), small molecule, peptide, or peptidomimetic.
The disclosed compositions and methods can be used to treat any disease or condition that involves aberrant integrin αvβ3 expression. For example, in some embodiments, the method treats a fibrotic disease, such as atherosclerosis, asthma, cardiac fibrosis, muscle fibrosis, pancreatic fibrosis, bone-marrow fibrosis, interstitial liver fibrosis, cirrhosis of liver and gallbladder, scleroderma, pulmonary fibrosis, diffuse parenchymal lung disease, idiopathic interstitial fibrosis, interstitial pneumonitis, desquamative interstitial pneumonia, respiratory bronchiolitis, interstitial lung disease, acute interstitial pneumonitis, nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, lymphocytic interstitial pneumonia, renal fibrosis, or chronic kidney disease. In some embodiments, the method inhibits or prevents fibrosis and/or scarring of a lesion in the subject.
In some embodiments, the method treats osteoporosis. Osteoporosis is cause by overly active bone resorption by activated osteoclast activity. Activated osteoclast cells express high levels of integrins αvβ3. Extracellular PKM2 likely plays a role in osteoclast activation and apoptosis resistance. Thus, the disclosed PKM2 antagonists may be effective for osteoporosis treatment.
In some embodiments, the method treats rheumatoid arthritis (RA), related rheumatic diseases and arthropathies, or autoimmune disease. These diseases are all involved in activation of macrophage by activation of integrin αvβ3 signaling.
Also disclosed is a pharmaceutical composition that comprises neutralizing antibodies (e.g., humanized antibodies or fragments) that specifically disrupts the binding of pyruvate kinase isoform M2 (PKM2) to integrin αvβ3, and a pharmaceutically acceptable carrier.
The details of one or more embodiments of the presently discloses subject flatter are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the presently disclosed subject matter will be apparent from the description and drawings, and from the claims.
Definitions
The term “fibrosis” refers to any disease or condition involving excess fibrous connective tissue in an organ or tissue.
The term “neutralize” refers to the ability of an agent, such as an antibody, to specifically bind a ligand and in so doing block or inhibit the ligands biological activity, A neutralizing antibody is an antibody that inhibits or abolishes some biological activity of its target antigen.
The term “antibody” refers to natural or synthetic antibodies that binds or selectively bind a target antigen. The term includes polyclonal and monoclonal antibodies. In addition to intact immunoglobulin molecules, also included in the term “antibodies” are fragments or polymers of those immunoglobulin molecules, and human or humanized versions of immunoglobulin molecules that selectively bind the target antigen.
A “monoclonal antibody” can be obtained from a substantially homogeneous population of antibodies, i.e., the individual antibodies within the population are identical except for possible naturally occurring mutations that may be present in a small subset of the antibody molecules. Monoclonal antibodies include “chimeric” antibodies in which a portion of the heavy and/or light chain is identical with or homologous to corresponding sequences in antibodies derived from a particular species or belonging to a particular antibody class or subclass, while the remainder of the chain(s) is identical with or homologous to corresponding sequences in antibodies derived from another species or belonging to another antibody class or subclass, as well as fragments of such antibodies, as long as they exhibit the desired antagonistic activity, Monoclonal antibody can be derived from species including but not limited to rabbits and mice.
The terms “peptide,” “protein,” and “polypeptide” are used interchangeably to refer to a natural or synthetic molecule comprising two or more amino acids linked by the carboxyl group of one amino acid to the alpha amino group of another.
“Activities” of a protein include, for example, transcription, translation, intracellular translocation, secretion, phosphorylation by kinases, cleavage by proteases, hemophilic and heterophilic binding to other proteins, ubiquitination.
The term “peptidomimetic” refers to a mimetic of a peptide which includes some alteration of the normal peptide chemistry. Peptidomimetics typically enhance some property of the original peptide, such as increase stability, increased efficacy, enhanced delivery, increased half life, etc. Methods of making peptidomimetics based upon a known polypeptide sequence is described, for example, in U.S. Pat. Nos. 5,631,280; 5,612,895; and 5,579,250. Use of peptidomimetics can involve the incorporation of a non-amino acid residue with non-amide linkages at a given position.
The term “specifically binds” refers to a binding reaction which is determinative of the presence of the antigen or receptor in a heterogeneous population of proteins and other biologies. Generally, a first molecule (e.g., antibody) that “specifically binds” a second molecule (e.g., antigen) has an affinity constant (Ka) greater than about 105 M−1 (e.g., 106 M−1, 107 M−1, 108 M−1, 109 M−1, 1010 M−1, 1011 M−1, and 1012 M−1 or more) with that second molecule.
The term “subject” refers to any individual who is the target of administration or treatment. The subject can be a vertebrate, for example, a mammal. Thus, the subject can be a human or veterinary patient. The term “patient” refers to a subject under the treatment of a clinician, e.g., physician.
The term “therapeutically effective” refers an amount of composition that is sufficient to ameliorate one or more causes or symptoms of a disease or disorder. Such amelioration only requires a reduction or alteration, not necessarily elimination of the disease or disorder.
The term “pharmaceutically acceptable” refers to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problems or complications commensurate with a reasonable benefit/risk ratio.
The term “treatment” refers to the medical management of a patient with the intent to cure, ameliorate, stabilize, or prevent a disease, pathological condition, or disorder. This term includes active treatment, that is, treatment directed specifically toward the improvement of a disease, pathological condition, or disorder, and also includes causal treatment, that is, treatment directed toward removal of the cause of the associated disease, pathological condition, or disorder. In addition, this term includes palliative treatment, that is, treatment designed for the relief of symptoms rather than the curing of the disease, pathological condition, or disorder; preventative treatment, that is, treatment directed to minimizing or partially or completely inhibiting the development of the associated disease, pathological condition, or disorder; and supportive treatment, that is, treatment employed to supplement another specific therapy directed toward the improvement of the associated disease, pathological condition, or disorder.
The term “inhibit” refers to a decrease inn an activity, response, condition, disease, or other biological parameter. This can include but is not limited to the complete ablation of the activity, response, condition, or disease. This may also include, for example, a 10% reduction in the activity, response, condition, or disease as compared to the native or control level, or control levels.
With respect to
Antibodies/PKM2 Antagonist
In one specific embodiment, the PKM2 or PKM2 Binding Sites antagonist is an antibody. Antibodies that can be used in the disclosed compositions and methods include whole immunoglobulin (i.e., an intact antibody) of any class, fragments thereof, and synthetic proteins containing at least the antigen binding variable domain of an antibody. The variable domains differ in sequence among antibodies and are used in the binding and specificity of each particular antibody for its particular antigen. However, the variability may not be evenly distributed through the variable domains of antibodies and may be concentrated in three segments called complementarity determining regions (CDR.$) or hypervariable regions both in the light chain and the heavy chain variable domains. The more highly conserved portions of the variable domains are called the framework (FR). The variable domains of native heavy and light chains each comprise four FR regions, largely adopting a beta-sheet configuration, connected by three CDRs, which form loops connecting, and in some cases forming part of, the beta-sheet structure. The CDRs in each chain are held together in close proximity by the FR regions and, with the CDRs from the other chain, contribute to the formation of the antigen binding site of antibodies. Therefore, the disclosed antibodies contain at least the CDRs necessary to bind PKM2 and inhibit the binding/interaction of PKM2 and integrin αvβ3.
Methods for generating monoclonal antibodies, including fully human monoclonal antibodies are known in the art. Any such known methods can be used in the context of this application to make human antibodies that specifically bind to PKM2 or PKM2 Binding Sites. Using known method for generating monoclonal antibodies, high affinity chimeric antibodies to PKM2 or PKM2 Binding Sites are initially isolated having a human variable region and a mouse constant region. As in the experimental section below, the antibodies are characterized and selected for desirable characteristics, including affinity, selectivity, epitope, etc. The mouse constant regions are replaced with a desired human constant region to generate the fully human antibody of the invention, for example wild-type or modified IgG1 or IgG4. While the constant region selected may vary according to specific use, high affinity antigen-binding and target specificity characteristics reside in the variable region.
To screen for antibodies which bind to a particular epitope (e.g., those which block binding of IgE to its high affinity receptor), a routine cross-blocking assay such as that described in Harlow and Lane (1990) supra can be performed. Other methods include alanine scanning mutants, peptide blots (Reineke (2004) Methods Mol Biol 248:443-63) (herein specifically incorporated by reference in its entirety), or peptide cleavage analysis. In addition, methods such as epitope excision, epitope extraction and chemical modification of antigens can be employed (Tomer (2000) Protein Science 9:487-496) (herein specifically incorporated by reference in its entirety).
In some embodiments, the PKM2 antagonist is an antibody including a heavy chain variable region and a light chain variable region. In some embodiments, the antibody specifically binds to PKM2 at domain A (α-helix 6′ to α-helix 6, and α-helix 7′). In some embodiments, the antibody binds to domain B: (β-sheet 1 and β-sheet 5). In some embodiments, the antibody binds to domain C (α-helix 5 to β-sheet 4). In some embodiments, the antibody specifically recognizes example sequence elements and other sequences of PKM2 that are involved in interacting with integrin αvβ3. Non-limiting examples of the specific sequences include Domain A α-helix 6, ARGDLGIEIPAEKVFLAQKMMIGRCNR and α-helix 7′ QMLESMIKKP, Domain B beta-sheet 1 EVELKKGAT and beta-sheet 5 ISLQVKQKGA, and Domain C α-helix 5 DVDLRVNFAMNVGKA and beta-sheet 4 KKGDVVIVLTGWR.
In one specific embodiment, the PKM2 antagonist is capable of binding the following sequences of PKM2: Domain A helix 6 (ARGDLGIEIPAEKVFLAQKMMIGRCNR) and α-helix 7′ (QMLESMIKKP), Domain B β-sheet 1 (EVELKKGAT) and β-sheet 5 (ISLQVKQKGA) Domain C α-helix 5 (DVDLRVNFAMNVGKA) and β-sheet 4 (KKGDVVIVLTGWR).
In some embodiments, the presently disclosed subject matter relates to an antibody comprising a heavy chain variable region and a light chain variable region, wherein said antibody specifically binds to at least one PKM2 domain selected from a group consisting of domain A, domain B and domain C.
Also disclosed are fragments of antibodies which have bioactivity. The fragments, whether attached to other sequences or not, include insertions, deletions, substitutions, or other selected modifications of particular regions or specific amino acids residues, provided the activity of the fragment is not significantly altered or impaired compared to the nonmodified antibody or antibody fragment.
Techniques can also be adapted for the production of single-chain antibodies specific for PKM2. A single chain antibody can be created by fusing together the variable domains of the heavy and light chains using a short peptide linker, thereby reconstituting an antigen binding site on a single molecule. Single-chain antibody variable fragments (scFvs) in which the C-terminus of one variable domain is tethered to the N-terminus of the other variable domain via a 15 to 25 amino acid peptide or linker have been developed without significantly disrupting antigen binding or specificity of the binding. The linker is chosen to permit the heavy chain and light chain to bind together in their proper conformational orientation.
Divalent single-chain variable fragments (di-scFvs) can be engineered by linking two scFvs. This can be done by producing a single peptide chain with two VH and two VL regions, yielding tandem scFvs. ScFvs can also be designed with linker peptides that are too short for the two variable regions to fold together (about five amino acids), forcing scFvs to dimerize. Diabodies have been shown to have dissociation constants up to 40-fold lower than corresponding scFvs, meaning that they have a much higher affinity to their target. Still shorter linkers (one or two amino acids) lead to the formation of trimers (triabodies or tribodies). Tetrabodies have also been produced. They exhibit an even higher affinity) their targets than diabodies.
Optionally, the antibodies are generated in other species and “humanized” for administration in humans. Antibodies can be humanized with retention of high affinity for the antigen and other favorable biological properties. To achieve this goal, humanized antibodies can be prepared by a process of analysis of the parental sequences and various conceptual humanized products using three dimensional models of the parental and humanized sequences. Computer programs are available which illustrate and display probable three-dimensional conformational structures of selected candidate immunoglobulin sequences. Inspection of these displays permits analysis of the likely role of the residues in the functioning of the candidate immunoglobulin sequence, i.e., the analysis of residues that influence the ability of the candidate immunoglobulin to bind its antigen. In this way, FR residues can be selected and combined from the consensus and import, sequence so that the desired antibody characteristic, such as increased affinity for the target antigen(s), is achieved. In general, the CDR residues are directly and most substantially involved in influencing antigen binding.
The targeting function of he antibody can be used therapeutically by coupling the antibody or a fragment thereof with a therapeutic agent. Such coupling of the antibody or fragment (e.g., at least a portion of an immunoglobulin constant region (Fc)) with the therapeutic agent can be achieved by making an immunoconjugate or by making a fusion protein, comprising the antibody or antibody fragment and the therapeutic agent.
Peptides
In some embodiments, the PKM2 antagonist is a peptide. Peptides that specifically bind PKM2, a PKM2 Binding Site or integrin αvβ3 can be identified using routine methods, such as phage display and yeast two-hybrid assays.
The disclosed peptides generally contain at least one segment that selectively hinds PKM2. The disclosed binding peptides can have a variety of lengths and structures as described herein. Generally, the lengths can range from peptide to polypeptide length, and all such lengths are encompassed as described herein. Merely for the sake of convenience, the disclosed peptides and polypeptides generally are referred to herein as “polypeptides” but it is intended that use of this term encompasses such compositions that could be considered peptides, unless the context clearly indicates otherwise.
In some embodiments, the binding peptide is a non-active fragment of integrin αvβ3, e.g., containing the binding/interaction site(s) for PKM2 but not other domains necessary for activation of integrin αvβ3.
Pharmaceutical Formulations
A pharmaceutical compositions containing therapeutically effective amounts of one or more of the disclosed PKM2 or PKM2 Binding Site antagonists in a pharmaceutically acceptable carrier is disclosed. Pharmaceutical carriers suitable for administration of the disclosed PKM2 or PKM2 Binding Site antagonists include any such carriers known to those skilled in the art to he suitable for the particular mode of administration. In one embodiment, the pharmaceutical composition comprises a molecule that specifically binds pyruvate kinase isoform M2 (PKM2) and inhibits the binding of PKM2 to integrin αvβ3, and a pharmaceutically acceptable carrier. The molecule agent can include a neutralizing antibody, a humanized antibody, and a monoclonal antibody. The monoclonal antibody can have a heavy chain variable region and a light chain variable region, and wherein said antibody specifically binds to at least one PKM2 domain selected from a group consisting of domain A, domain B and domain C.
In addition, the compounds may be formulated as the sole pharmaceutically active ingredient in the composition or may be combined with other active ingredients. For example, the compounds may be formulated or combined with known NSAIDs, anti-inflammatory compounds, steroids, and/or antibiotics,
The PKM2 antagonists may be formulated into suitable pharmaceutical preparations such as solutions, suspensions, tablets, dispersible tablets, pills, capsules, powders, or sustained release formulations.
In one specific embodiment, the compositions are formulated for single dosage administration. To formulate a composition, the weight fraction of compound is dissolved, suspended, dispersed or otherwise mixed in a selected carrier at an effective concentration such that the treated condition is relieved or one or more symptoms are ameliorated.
The active compound is included in the pharmaceutically acceptable carrier in an amount sufficient to exert a therapeutically useful effect in the absence of undesirable side effects on the patient treated. The therapeutically effective concentration may be determined empirically by testing the compounds in in vitro, ex vivo and in vivo systems, and then extrapolated therefrom for dosages for humans.
The concentration of active compound in the pharmaceutical composition will depend on absorption, inactivation and excretion rates of the active compound, the physico chemical characteristics of the compound, the dosage schedule, and amount administered as well as other factors known to those of skill in the art.
The dosage and schedule for administration of a therapeutic antibody used in the disclosed methods can. be determined by one of skill in the art. For example, the dosage of the antibody can range from about 0.1 mg/kg to about 50 mg/kg, typically from about 1 mg/kg to about 25 mg/kg. In particular embodiments, the 4 antibody dosage is 1 mg/kg, 3 mg/kg, 5 mg/kg, 10 mg/kg, 15 mg/kg, 20 mg/kg or 25 mg/kg. The dosage schedule for administration of the antibody can vary depending on the desired aggressiveness of the therapy, as determined by the practitioner.
An exemplary treatment regime entails administration once per every two weeks or once a month or once every 3 to 6 months. Antibody is usually administered on multiple occasions. Intervals between single dosages can be weekly, monthly or yearly. Alternatively, antibody can be administered as a sustained release formulation, in which case less frequent administration is required. Dosage and frequency vary depending on the half-life of the antibody in the patient. In general, human antibodies show the longest half-life, followed by humanized antibodies, chimeric antibodies, and nonhuman antibodies. The dosage and frequency of administration can vary depending on whether the treatment is prophylactic or therapeutic. In prophylactic applications, a relatively low dosage is administered at relatively infrequent intervals over a long period of time. Some patients continue to receive treatment for the rest of their lives. In therapeutic applications, a relatively high dosage at relatively short intervals is sometimes required until progression of the disease is reduced or terminated, and until the patient shows partial or complete amelioration of symptoms of disease. Thereafter, the patent can be administered a prophylactic regime.
Methods
Methods are disclosed for inhibiting or preventing diseases associated with abberant integrin αvβ3 in a subject that involve administering to the subject a composition containing an effective amount of PKM2 antagonist in a pharmaceutically acceptable recipient. In specific embodiments, the PKM2 antagonist specifically binds PKM2 and inhibits the binding/interaction of PKM2 to integrin αvβ3 in the subject. In sonic of these embodiments, the composition contains an effective amount of PKM2 antagonist to inhibit the binding/interaction of PKM2 to integrin αvβ3 by at least 10% to 100%, including by about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100%.
On specific embodiment includes methods for treating a disease associated with aberrant integrin αvβ3 expression in a subject, comprising administering to the subject an effective amount of a composition comprising a pyruvate kinase isoform M2 (PKM2) antagonist, wherein the PKM2 antagonist inhibits the binding of PKM2 to integrin αvβ3. The PKM2 antagonist can be an antibody that selectively binds PKM2. The PKM2 antagonist can be a monoclonal antibody. The monoclonal antibody comprises a heavy chain variable region and a light chain variable region, and wherein said antibody specifically binds to at least one PKM2 domain selected from a group consisting of domain A, domain B and domain C. In some embodiments, the PKM2 antagonist is a peptide or peptidomimetic that selectively binds PKM2.
Administration
The disclosed pharmaceutical compositions containing PKM2 binding molecules may be administered in a number of ways to achieve therapeutically effective amounts of the PKM2 binding molecules in the circulation of the subject. For example, the disclosed compositions can be administered intravenously, intraperitoneally, intramuscularly, subcutaneously, intracavity, or transdermally. The compositions may be administered parenterally, ophthalmically, vaginally, rectally, intranasally, or by inhalant.
Parenteral administration of the composition, if used, is generally characterized by injection. Injectables can be prepared in conventional forms, either as liquid solutions or suspensions, solid forms suitable for solution of suspension in liquid prior to injection, or as emulsions. A revised approach for parenteral administration involves use of a slow release or sustained release system such that a constant dosage is maintained.
The disclosed compositions may be administered prophylactically to patients or subjects who are at risk for diseases associated with abberant integrin αvβ3. Thus, the method can further comprise identifying a subject at risk for fibrosis prior to administration of the disclosed compositions.
The exact amount of the compositions required will vary from subject to subject, depending on the species, age, weight and general condition of the subject, the severity of the allergic disorder being treated, the particular composition used, its mode of administration and the like. Thus, it is not possible to specify an exact amount for every composition. However, an appropriate amount can be determined by one of ordinary skill in the art using only routine experimentation given the teachings herein. For example, effective dosages and schedules for administering the compositions may be determined empirically, and making such determinations is within the skill in the art. The dosage ranges for the administration of the compositions are those large enough to produce the desired effect in which the symptoms disorder are effected. The dosage should not be so large as to cause adverse side effects, such as unwanted cross-reactions, anaphylactic reactions, and the like. Generally, the dosage will vary with the age, condition, sex and extent of the disease in the patient, route of administration, or whether other drugs are included in the regimen, and can be determined by one of skill in the art. The dosage can be adjusted by the individual physician in the event of any counter indications. Dosage can vary, and can be administered in one or more dose administrations daily, for one or several days. Guidance can be found in the literature for appropriate dosages for given classes of pharmaceutical products. A typical daily dosage of the antibody used alone might range from about 1 mg/kg to up to 100 mg/kg of body weight or more per day, depending on the factors mentioned above.
The frequency of dose will depend on the half-life of the molecule and the duration of its effect. If the molecule has a short half-life (e.g. 2 to 10 hours) it may be necessary to give one or more doses per day. Alternatively, if the molecule has a long half life (e.g. 2 to 15 days) it may only be necessary to give a dosage once per day, once per week or even once every 1 or 2 months.
A number of embodiments of the presently disclosed subject matter have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the presently disclosed subject matter. Accordingly, other embodiments are within the scope of the following claims.
The following Examples are intended to show certain embodiments of the present invention. They are exemplary of the present invention and are not to be construed as being limiting thereof. Thus, the compositions described in the Examples are non-limiting examples of embodied compositions of the presently disclosed subject matter.
Extracellular PKM2 Promotes Myofibroblast Differentiation
Experiments were conducted to determine whether rPKM2 could induce myofibroblast differentiation of cultured fibroblast cells. rPKM2 was added to the culture medium of HDFa cells. IF staining of the cells revealed that extracellular PKM2 promotes formation of stress-fiber bundle of_α-SMA with a typical pattern of myofibroblast (
PKM2 Promotes Myofibroblast Differentiation by Acting on Integrin αvβ3
The extracts were prepared from the rPKM2 crosslinked cells. The crosslinked proteins were separated by His-tag pull-down. Immunoblot of PKM2 revealed a rPKM2 crosslinked protein. The rPKM2 crosslinked protein band was sliced out and digested by trypsin, and subsequently analyzed by MALDI-tof/tof. The MS-analyses showed that rPKM2 crosslinked to integrin α3 (
An open question was how the extracellular PKM2 that acts on integrins αvβ3 upregulates α-SMA expression. The regulatory effects was not mediated via Smad pathway. TGFβ can promote myofibroblast differentiation by a Smad independent pathway via activation of PI3K (Wilkes M C, et al. Cancer Res. 2005 65(22):10431-40). On the other hand, activation of integrin signaling leads to activation of PI3K (Wegener K L, et al. Mol Membr Biol. 2008 25(5):376-87).
Antibodies Interrupt the Interaction Between PKM2 and Integrin αvβ3
PKM2 interacts with integrin αvβ3, and activates the integrin signaling (
Assays for Analyses the Effective of Antibody that Interruption of PKM2 and Integrin αvβ3 Interaction.
ELISA assay. Recombinant PKM2 was coated on ELISA plates. Recombinant integrin αvβ3 along with test antibody or IgG (as control) were added into the PKM2 coated plates. Plates were washed several times. Binding of the integrin αvβ3 to PKM2 were measured using antibody against integrin αvβ3 (
Recombinant integrin αvβ3 were coated on ELISA plates. Recombinant PKM2 along with test antibody or IgG (as control) were added into the integrin αvβ3 coated plates. Plates were washed several times. Binding of the PKM2 to integrin αvβ3 was measured using antibody against PKM2 (
Cell attachment assay. Cell culture plates were coated with recombinant PKM2. HUVEC or COS-7 cells along with test antibody of IgG (as a control) ˜2-5 μM were added to the plates. After 50 minutes incubation. The cells attached to the plates were counted (
Liver fibrosis was induced with Balb/C mouse by i.p. administration of TAA and 10% ethanol in drinking water. Recombinant bacterially expressed PKM2 (rPKM2), PKM1 (rPKM1), or buffer was added into the fibrosis induction 15 days after first dose of TAA administration (
A pair of rabbit monoclonal PKM2 antibodies was employed to disrupt the PKM2-integrin interaction (16-2)—one was active and the other was not. The other one (21-3) is not (
Lung fibrosis of Balb/C mice was induced by Bleomycin treatment. At end of fibrosis induction (5 weeks), purified PKM2 antibody from hybridoma line were administered at 4 mg/kg i.p. for 10 doses. At the end of treatment, animals were sacrificed. Lungs from treated animals were collected and pictured (not shown). It is clear that bleomycin induced strong lung fibrosis. Fibrosis features on the lung surface of PKM2 antibody treated group were clearly less compared to that of IgG, buffer, and pirfenidone treated groups. Sirius red stain of lung tissue sections revealed substantial decrease (percent of total area) in collagen contents and density, indicating resolve of collagen accumulation in fibrotic lung by the PKM2 antibody treatment (
Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of skill in the art to which the presently disclosed subject matter belongs. Publications cited herein and the materials for which they are cited are specifically incorporated by reference.
Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the presently disclosed subject matter as described herein. Such equivalents are intended to be encompassed by the following claims.
As used in this specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise.
This application claims the benefit of U.S. Provisional Patent Application No. 62/121,338, filed Feb. 26, 2015, which is incorporated herein by this reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US16/19705 | 2/26/2016 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62121338 | Feb 2015 | US |
